How the 'Friday the 13th' superstition got started

Fear of Friday the 13th, also known as friggatriskaidekaphobia , plagues our society. The diagnosis brings together “Frigg,” a Norse goddess and Friday’s namesake, and “triskaidekaphobia,” fear of the number 13 in general.

Every year, the world loses $700 to $US800 million on Friday the 13th because people won’t conduct business as usual. Many especially refuse to fly.

So where does this superstition originate? The roots link back to religion — of all denominations and time periods.

History of a superstition

First and foremost, the Last Supper’s 13th guest (and last apostle), Judas, supposedly betrayed Jesus. Then, His Crucifixion occurred on a Friday. Some scholars also believe Eve tempted Adam on a Friday.

But the number thirteen’s cursed beginnings fall outside the rise of Christianity, too. A similar story occurs in Norse mythology. The 11 closest friends of Odin, the father of all gods, chose to dine together when Loki, the god of evil and chaos, crashed the party. One of the gods, Balder, the god of joy and happiness, died that evening.

Much later, King Philip IV of France certainly didn’t help by ordering the persecution of the Knights Templar on Friday, October 13, 1307. In the following years, several thousand faced torture and execution.

If those tales don’t convince you, maths also has a stake in why people get bad vibes from the number thirteen. First, 12 appears a lot in our culture — 12 months in a year, 12 hours on a clock, 12 signs of the zodiac, 12 apostles of Jesus. We love 12.

12 is a “pseudoperfect” number, according to Wolfram. The sum of some of its divisors equals the whole number. For example, 1, 2, 3, 4, and 6 go into 12. Both 2+4+6 and 1+2+3+6 equal 12.

Regardless of where, when, or how this superstition started, we’ve perpetuated our own fear. “If nobody bothered to teach us about these negative taboo superstitions like Friday the 13th, we might in fact all be better off,” Stuart Vyse, psychology professor at Connecticut College in New London, told National Geographic.

*This article was originally published on September 13, 2013. See the original here.